Turning on time-aware capability

I am trying to create a time slider from a dynamic Json url but it is not going too well. I parsed through the data and manually created a feature layer through the help of the following link: Feature collection | ArcGIS API for JavaScript but can't seem to get any time information.

I have created a esriFieldTypeDate field in the layer definition, formatted the date in YYYYMMDDHHMMSS format and defined the feature layer as Featurelayer.MODE_SNAPSHOT. However when I was trying to access the feature layer's timeinfo properties, the console displayed the value as undefined.

Sorry I must have skipped reading where you were creating the layer based on a feature collection. So the Feature Collection does not have a time extent and that is why it is null. Juts adding an esriFieldTypeDate field does not make the data time aware or produce a time extent. So you need to look at the docs for TimeExtent: